Method of sizing paper



Patented Jan. 12, 1954 UNITED STATES PATENT OFFICE METHOD OF SIZING PAPER Arthur B. Bakalar, San Francisco, and Robert D.

Sullivan, Oakland, Calif., assignors to Shell De- 1 velopment Company, San Francisco, -Calif., a

corporation of Delaware No Drawing. Application August 2, 1948,

Serial No. 42,149 12 Claims. (01152-3) This invention relates to the sizing of fibrous materials such as paper, cardboard, textile threads or fabrics, imitation leather, and the like. It deals with a new method of carrying out such sizing operations in a more advantageous manner and with novel compositions of matter which are not only valuable sizing agents but also have other useful applications.

The usual procedure in sizing fibrous materials sitions which may be readily emulsified and .will form stable emulsions of relatively small/uniform particle size capable of imparting good water-resistance to fibers of all types. Another object is to provide a convenient and efiicient method of sizing fibrous materials which may be successfully used with viscous or solid sizing agents of the hydrocarbon type. A further object is to make available sized articles of manuis to contact intimately an aqueous dispersion of facture, particularly sized paper or other celluthe size with the fibers and then precipitate the losic articles having desirable water-resistance. size on the fibers by adding a suitable precipitant. Still another object is to provide new emulsifiable Thus, for example, in sizing paper pulp, the discompositions which not only are useful sizing persion of size is generally added to the pulp in agents but also have other important uses. Furthe beater or Holland machine and is there prether objects and advantages of the invention will cipitated on the fibers with paper makers alum be apparent from the following description of or other acid-acting agents. In this method of some of its preferred applications, it being undersizing it is advantageous to use a sizing agent stood that the invention is not limited thereto which can be prepared a a highly concentrated, but is broadly applicable in the scope set out in stable aqueous dispersion or emulsion of small the appended claims.

volume suitable for shipment and storage prior It has. been found that fibrous materials, parto use and capable of ready dilution to the relaticularly fibers of cellulose and the like, may be tively low concentration preferred in sizing withadvantageously sized with hydrocarbons in the out separation difficulties. A number of sizing presence of a polyphosphoric acid compound, agents, such as rosin, for instance, meet these repreferablytogether with a mutual solvent for the quire'mentsverywell but are relatively expensive to use. Another suitable type of sizing agent is the emulsions of cyclic extracts of petroleum prepared with naphthenates of naphthenic acids having acid numbers of less than 200, which are described and claimed in copending application of Theodore F. Bradley, Serial No. 33,218, filed June 15, 1948. These sizing agents are not only relatively cheap but also are highly efiective water-repelling agents. However, especially when using hydrocarbons of high viscosity, it is necessary in order to obtain uniform emulsions of small particle size to use extended agitation or other special emulsification procedures which add to the cost of operation and are undesirable. This type of difliculty is also encountered with other types of sizing agents such as many viscous resins, both natural and synthetic, waxes of high melting point, bituminous materials, asphalts, tars, etc., and has, in many cases, made their use impractical in spite of their desirable sizing properties.

An important object of the present invention is to overcome the foregoing disadvantages of these sizing agents and to provide sizing compopolyphosphoric acid compound and the sizing agent used. Relativelysmall amounts ofpolyphosphoric acid compounds, preferably a salt or ester of a polyphosphoric acid, introduced into thesizing compositions containing viscous sizing agents, particularly hydrocarbons, markedly improve their properties making them easy to handle according to ordinary sizing procedures While giving excellent sizing characteristics. These new sizing compositions, comprising 'a viscous, sizing agent together with a polyphosphoric acid compound, make it possible to supply the paper industry with a concentrated emulsible mixture which is readily dispersed in water and can be applied in the customary way in emulsion sizing. Emulsions produced from these compositions have the advantage of being capable of phase inversion. Thus, concentrated water-inoil'type emulsions can be prepared fromsizing agents having viscosities of 400 SUS at, 210 F. or higher viscosities without the use of a colloid mill or other costly dispersion methods due to the presence of the polyphosphoric acidcompound. These water-in-oil type of emulsions are readily diluted to form stable oil-in-Water type emulsions of any desired concentration which are excellent sizing agents when applied in the usual manner. By preparing the new compositions either as emulsible mixtures of sizing agent and polyphosphoric acid compounds or as a water-in-oil or a concentrated oil-in-water type emulsion, the disadvantages of shipping and storing emulsions containing large percentages of water are avoided.

Among the polyphosphoric acid compounds which have been found-to be suitable in the new sizing compositions oi" the invention, the derivatives of the polymetaphosphoric acids, (HPOsh, and of the polyphosphoric acids of the pyrophosphoric acid type, Hx+2PxO3x+l, have been found to be especially advantageous. In these formulae of the preferred acids, is at least 2, generally 2 to 6, although higher polyphosphatesmay alsobe. used. Salts of these polyphosphorie acids are. a particularly useful form of the phosphoric acid compounds used according to the invention.

Such salts are readily preparedQfor example,

fusing mixtures of orthophosphoric acid salts with bases or by fusing mixtures of salts of monophosphoric acids and lielyphosphoric acids. In this way a, large numberof difiierent polyphosphoric acid compounds: can be produced, each differing only slightly from its adjacent members of the series and all being effective in the process of the invention.

When usingpolyphosphoric acid salts in. the new sizing compositions, it; is preferable as a rule to choose; water-soluble. salts, although by the use of suitable mutual solvents, it. is feasible to employ salts. of very low. solubility in water which might be classed as waterdnsoluble salts. Ammonium or alkali metal salts; are. particularly useful. Mixed salts as well as simple salts may be used, and with the. polybasic polyphosp-horic acids of high molecular weights, the mixed salts having both monovalent. and polyvalent anions are particularlysuitable. Thus, mixed salts having alkaline earth metal or aluminum or zinc. ions together with alkali metal ions, for example, the

calcium sodium or magnesium potassium or aluminum-ammonium salts of high polyphosphoric acids, can be used advantageously. With such salts it is preferred that the ratio of monovalent anions to polyvalent. anions present be high, as the water solubility is thereby improved.

Representative examples of other suitable polyphosphoric acid salts are, for instance, sodium trimetaphosphate (NaPOsla, sodium tetrametaphosphate (NaPOsM, sodium hexametaphosphate (NaPOaM, tetrasodium pyrophosphate NarPzoq, disodium dihydrogen pyrophosphate NazHzPzOv, trisodiuxn hydrogen pyrophosphate NasHPz-Ov, sodium tetraphosphate N36P4013, the complex fusion product from two moles of monosodium dihydrogen phosphate and one mole of disodi'um monohydrogen phosphate NaaPsOw. As a rule the salts havin a pH of '7 or higher are preferred and for this reason the salts of polyphosphoric acidsof the pyrop-hcsphoric acid type Hx+2PrO3x+l are preferred over the polymet-aphosphoric acid salts. However, by the use of buffers or the like any of the polyphosphori'c acid salts may be successfully used. Buffers suitable for maintaining the desired alkalinity during sizing are, for example, sodium silicate, sodium borate, the orthophosphates such as disodium orthophosphate, etc.

Thiopolyphosphates. may be used in place of or in conjunction with the, foregoing salts. Examplesof salts of this typejwhich are. useful are,

for instance, sodium monothiotetraphosphate 4 NasProizs and sodium trithiotetraphosphate N316P4010S3. These compounds have the same general efiiciency as the other water-soluble polyphosphoric acid compounds in improving sizing according to the invention.

Another type of polyphosphoric acid compound which is eiiective in the compositions and process of the invention is the esters of these acids. Esters of aromatic hydroxy compounds, especially esters of polyhydroxy aromatic compounds such as pyrogallol, resorcinol, phljoroglucinol, hydroxyquinol, catechol, gallic acid, protocatechuric acid, digallic acid, ellagic acid, tannic acid, the tannins, tannin-like bodies, etc., are especially useful. Other suitable esters are, for instance, the esters of water-soluble monoand polyhydric alcohols such. as: ethyl, isopropyl and tertiary butyl alcohols, glycerol, giycol, pentaerythritol, arabitol, polyvinyl and polyallyl alcohols, and the like. The pyrophosphoric and tetraphosphoric acid esters are equally suitable. Amino-substituted esters are an especially advantageous subgroup of esters useful in the new process. Esters of this type from amino anthraquinones are applicable according to the present invention. Hydroxyalkylaminoanthraquinones, wherein the hydroxyalkyl radical or radicals are attached to the aromatic nucleus through an intervening amino group, are emphasized in the patent but amino esters having the amino groups or groups otherwise attached to the molecule may also be used. Thus, the amino group may be linked to an arcmatic nucleus either directly or through an intervening ester radical or acyl residue or by other groups. Suitable amino-substituted aromatic compounds from which the phosphoric acid esters may be derived include, for example, amino-benzene, amino-toluene, amino-naphthalene, aminoanthracene, amino-substituted phenols such, for instance, as the amino-phenols, amino-cresols, amino resorcinols, amino -naphthols, aminopyrogallols, amino-benzyl alcohols, amino-cinnamyl alcohols, amino-anisoles, amino-acetephenones, amino benzop-henones, amino quinones, amino-benzaldehydes, etc. When the starting amino compound contains a hydroxy group as in the alcohols or phenols, the esters may be readily prepared by reaction with pyro, tetra orother polyphosphoric acid oranhydride or halogenlde to form the amino esters which are useful in the present invention. With nonhydroxy starting materials, or where further hydroxylationis desirable, a suitable hydroxyalkylamino aromatic compound may be prepared by reacting the aromatic amino compound with glycol monoand di-chlorohydrins or the corresponding chlorohydrins of glycerol or other polyhydricalcohols. This procedure is commonly carried out by dissolving the aromatic amino compound in a suitable inert solvent, adding the alkyl chlorohydrin, and refluxing until the reaction is substantially complete. the mixture is then made strongly alkaline with sodium or potassium hydroxide and the amine layer removed. After drying. thoroughly, it. may then be reacted with the polyphosphoric acid, anhydride, or halogenide. Tetraphosphoric acid is the preferred polyphosphoric acid for the synthesis. of these esters because it is readily available in anyhdrous form.

Addition products of methyl, ethyl, isopropyl, tertiary butyl and like esters of tyrosine, tryptophane, and creatine with the various polyphosphoric acids and their acid salts such, for instance, as mono-sodium dihydrogen pyrophosphate and the like, are equally useful or the more complex products of further polymerization such as i. e. ammonium hexaphosph'ate dinitride and products of higher molecular weight, may be used. Other water-soluble hexaphosphate dinitrides of any degree of polymerization such, for instance, as sodium hexaphosphate dinitrate or the corresponding potassium compound can likewise be employed, An alkali metal can replace either all the NH4 groups of ammonium hexaphosphate dinitride or only a portion thereof. Thus, ammonium hexaphosphate dinitride can be treated with alk-alies to a pH of approximately 8 without liberation of ammonia, but if caustic soda or soda ash is added beyond this point, the ammonium nitrogen is completely displaced and the pH will rise. The nuclear nitrogen, however, is not displaced by the addition of alkalies. Esters of these complex phosphates may be used instead of the salts. Thus, for example, the esters produced by reacting hydroxy organic compounds such as tannins, sugars, starches, cellulose, gums, lignins, aliphatic or aromaticalcohols; alkylolamine, :etc; with molten ammonium imidodiphosphoriciacid 1 are suitable inthe new process. These products are usually hard, brittle glasses which are soluble in water and probably involve condensation as well as esterification in their formation. Their structure has not been accurately determined but they have been found as a rule to be supe ior in the process of the invention to the imido diphosphoric acid salts, although these are themselves efiective when. used in suitable amounts, I M

As previously pointed out, the polyphosphoric acid compounds are preferably used with a solvent which is also substantially miscible with the sizing agent being used. Suitable mutual solvents are, for example, alcohols such as methyl, ethyl, normal propyl, isopropyl, normal or sec:- ondary butyl, the amyl alcohols, methyl isobutyl carbinol and the, like, glycols such as the hexylene glycol, etc, hydroxy derivatives of polyhydric alcohols such asthe monoor poly-glycol monoalkyl esters or ethershaving 1 to 4'carbo'n atoms in the 'alkyl group, ketones of the type of methyl ethyl ketone, mesityl oxide, diacetone alcohol, isophorone, methyl isobutylketone, etcl, esters of which ethyl formate, methyl lactate and dimethyl m-aleate are examples, aldehydes as acetaldehyde and acetaldol or the like, diethylene dioxide, morpholine, phenols, fand amines such as'butyl or amyl amines, thee'thanol amines, pyridines, etc. The particular solvent used should be'o'ne which boils at a temperature above that at which the sizing composition is prepared and/or used. Thus, when using sizing agents which are melted to facilitate their emulsific-ation, it is preferable to employ higher boiling solvents; however, it is seldomthatsolvents boiling above about C. are necessary.

The amount of polyphosphoric compound, or mixture of two or more such compounds, and solvent employed will depend toa certain extent upon the particular compound and'solvent chosen and'the sizing agent with which they are'to be used, but asa general rule it h'as'been found that about 0.25% to,10%', preferably 0.5%" to 2.5 of polyphosphoric' compound based on the weight of sizing agent present is satisfactory. Less than 0.05% of polyphosphoric acid compound gives insufiicientimprovement of the sizing composition, while more than 20% may be detrimental to the effectiveness of the size. Sufficient solvent should be used to maintain the polyphosphoric compound homogeneously 'distributed in the composition, but too great an excess is to be avoided since it may reduce the wator-resistance of the final sized product. Usually about one-half to ten times as much solvent by weight as polyphosphoric acid compound is suitable, two to about six times as much solvent being generally preferable.

Although other methods of incorporating the polyphosphoric acid compound in the sizing mix ture may be successfully used, one procedure which has been found convenient comprises adding an aqueous solution of the chosen polyphosphoric acidcompound to a mixture of the sizing agent and emulsifying agent which advantageously may alsocontain the. mutual solvent iisuch is to be used. Most: preferably, the sizing agent is melted and thoroughly mixed with an acid emulsifying agent-forming compound such as naphthenic acids. or rosin or an alkyl aryl sulfonic acid or the like, the mutual solvent is then added while continuing the mixing and heating, and then sufficient base to neutralize the emulsifying agent is run in together with the solution of the polyphosphoric acid compound. In this way emulsions of the Water-in-oil type can be obtained which are stable. readily p pa Without special expensive apparatus, and capable of phase inversion by dilution to produce oil-inwater type emulsions having excellent sizing properties.

The. preferred sizing. agentsfor use in the process and new compositions of the iny-ention, are hydrocarbons of higher molecular weight, most preferably the cyclic extracts of predominantly .aromatic and naphthenic nature, obtainable by extracting petroleum or related oils, including hydro e t on products of coal and he li e. with solvents which are selective for ne p raffinic constituents. A wide variety of polar solvents may be used for the; preparation of such extracts, liquid sulfur dioxide, phenol, cresylic acid, furfural, beta,beta-dic hlorethyl ether, nitrobenzene, the sulfolanes and sulfolenes, and the like being typical examples of suitable solvents. Combinaa tions. of solvents, as phenols with cresylic acid or liquid sulfur dioxide with benzene or toluene, for instance, are useful and the use of the so-called double solvent process employing mutually immiscible. solvents, e. g. cresylic acid with propane, also gives suitable extracts, There are also advantages in reextracting the initial extract with. a immiscible solvent to improve the selectivity of the extraction. Thu extraction of Edeleanu extracts of lubricating oils, with gasoline or the like has been, found; to improve the sizing properties of the compositions produced therefromv in accordance; with the invention. Extractive distillation may be used in place of or combination; with. the previously mentioned extraction methods.

Extracts of heavier petroleum oils such as the lubricating oils and residual stocks. are especially useful the new sizing compositions of the invention, but other fractions of, petroleum or related hydrocarbon products can also .be used successfully-as sources; of the extracts. The extracts may be derived, for example, from lubricant distillates or bright; oils or cylinder stocks which may, for instance, range in gravity from 159' to 8 API at 60- F. They may be obtained from any mixed typepe rol u oil such as Mid-Con.- tinent or Coastal or California crude. or, in lower yields, from Pennsylvania type oils. For usev in sizing in accordance with the invention, extracts boiling above 300 C.' at 760; mm, Hg pressure are preferred, and most preferably extracts boiling from about 125 C. to 300;; C. at 1 mm. Hg pressure are used. The more viscous extracts usually give the most desirable sizing properties and for this reason extracts having viscosities of at least 200 SUS atv 210 F. are preferred. Most preferably, extracts having viscosities of 400 'SUS at 210 F. or more; are used and there are Special advantages in using extracts having viscosities; of the order of; about 2,000 to 50,000 SUS at 21.0? E. Extracts. obtained from narrow fractions, as. describ d in U. Patent 2,115,960, m y be advantageously employed. It. is often advantageousto firactionate the initial. extract, toseperties; thus, for instance, it has, becnfound: that the. higher boiling-50% to '7'5.1%-of an Edeleanu extract. of lubricati-ng oil. gives: superior sizing judging. by permeability to; water of sized paper. Other typesof sizing agents which may be used include oils or waxes. These are useful when used either in combination or separately. Hydrocarbons such as lubricating oils, spindle oil, etc. may likewise be used. Various rubbers and synthetic resins such as are described, for example, in the article by E. G. Partridge entitled "Latex compounds for paper industry in India Rubber World, volume 118, pages 221 to 223 (May 1948), may be used as the sizing agent with phosphorus-containing compounds according to the present invention,

A wide variety of different emulsifying agents may be used in preparing the new emulsifiable compositions of the invention. Especially advantageous emulsifying agents are salts of naphthenic acids having acid numbers less than 200, preferably acid numbers of about 100 to 175, the acid number being the number of milligrams of potassium hydroxide which will neutralize the acids in a one-gram sample of the naphthenic acids. A suitable source of such naphthenic acids is the naphthenates produced in the refining of petroleum and its various products, particularly lubricating oil. The naphthenic. acidghaving the preferred low acid number may be separated from their mixtures with less desirable naphthenic acids of higher acid number by fractionally distilling off the latter and using only those naphthenic acids boiling above about 200 C. at 0.5 mm. Hg pressure. Particularly suitable are naphthenic acids boiling between about 250 C. and 350 C. at 0.5 mm. Hg pressure. Petroleum oils which boil above 2.00- C. at 0.5 mm. Hg pressure, especially fractions of lubricating oil or the like boiling between about 250 C. and 350 C. at 0.5 mm. Hg pressure, are preferred sources of the naplithenates used in the new compositions. However, other emulsifying agents, including the ordinary commercial naphthenates having acid numbers greater than 200, fatty acid soaps, higher alkyl sulfate salts, organic sulfonic acid salts, particularly alkyl aryl sulfonates having 8 to 18 carbon atoms in the alkyl group, rosin acid soaps and the like or mixtures of any of these may also be. successfully used. The amount of emulsifying agent which it will be most advantageous to use will vary somewhat with the type of emulsifier chosen and the particular sizing agent being emulsified but, as a rule, will corre spond toabout 3 to about, 7-5, more preferably 5. to .50, per cent by weight of the total weight of emulsifying agent. and hydrocarbon employed.

In preparing the emulsions bythe neutralization technique previously referred to. a number of different types of basic, compounds can be used. Hydroxidesor carbonates of alkali metals or ammonia are suitable, sodium or potassium hydroxides being preferred hydroxides, however, because of their relatively low cost. The corresponding, particularly the sodium. and potassium, carbonates require higher temperatures and are thus somewhat less preferable. Alkaline earth hydroxides such, for example, as calcium and magnesium hydroxides, etc. may also be used. For certain purposes, neutralization with. an organic. base such, for example, as aliphatic, alicyclic, or aromatic, primary, secondary or tertiaryamines or quaternary ammonium bases, is advantageous. Water-soluble amines such, for

9 instance, as dimethylamine, propylamine, cyclohexylamine, the ethanolamines, etc. may be used in such cases. The chosen base is preferably employed as an aqueous solution of about to about 30% concentration, most preferably about 5% to concentration. The most stable emulsions are prepared by the use of slightly less than the stoichiometric amount of base, preferably about 85% to 95% of the amount required for neutralization of the acid of the emulsifying agent. A pH of about 8 to 13, preferably 10 to l1.5, is advantageous in the final emulsion. If the initial emulsion is too acid or alkaline, it can be brought to the desired pH by adding a'suitable buffering agent.

The invention is, of course, not limited to the method of preparing the new emulsions described.

as other procedures are also applicable. Thus,

for example, it is feasible to produce highly-er fective sizes by intimately mixing a sizing agent such as a cyclic extract of lubricating oil fon instance, with an emulsifying agent such as previously neutralized naphthenic' or rosin acids and then adding a polyphosphoric acid comof relatively high viscosity, and anjemulsifier.

that'they not only are very eifectivein improving the water-resistance of fibrous materials but also arecapable of ready emulsification and form stable emulsions of the water-in-oil type with hydrocarbon-type sizing agents, particularly the cyclic extracts of petroleum which'maybe-readily inverted to emulsions of the oil-in-rwater type which are quite stable, yetare precipitable in the presence of paper fibers by the usual paper makers precipitants. This unusualcombination of desirable properties makes it feasible to prepare very cheaply highly effective sizing com positions as concentrated water-in-oil type emulsions which can be conveniently shipped at low cost, stored until needed, and readily diluted at the paper mill without difficulties from phase separation or loss in sizing power to form emulsions of the oil-in-water type which can be used for sizing in the same way as the conventional rosin emulsion sizes. Emulsions which contain at least 40% water, for example, 40% to 99% water or, as shown in Example I which follows, more than 99% water, can be thus used for siz- 1Q with the size but generally it is preferred to add it later in the process, thus providing adequate time for uniform distribution of the size before introducing the precipitant.

The amount of size which it will be most advantageous to employ will depend on the nature of the fibrous material being treated, the purcipitation, Ifnecessary, the pH may be controlled by adding dilute acid in the beater. About grams of aluminum sulfate per kilogram of dry stuff in'the beater gives satisfactory precipitaing. Thus, in sizing paper, for example, the

emulsions of the invention may be added to the all suitable, but paper malrers alum is preferred.

The precipitant may beadded to the fiber along tion. Too much aluminum in the paper should --be avoided as it adversely affects the permeability to water.

The following examples illustrate in greater detail some typical applications of the invention and show the advantageous results which may be obtained. 1

Example I A series of sizing compositions was prepared using a variety of furfural extracts of different viscosities as the sizing agent and sodium pyro phosphate as the polyphosphoric acid compound. In each case, 800 grams of the extract were heated to about C., 200 grams of wood rosin (FF) "and 40 grams of isopropyl alcohol were charged in that order to a jacketed Readco Internal Mixer preheated to about C. and. mixed for 5 minutes. 106 grams of a 20% solution of sodium hydroxide and 1 00 grams of a 75% solution of sodium pyrophosphate were then added, and the mixingcontinued for 15 minutes at 80 C. to 85 C. The resulting water-in-oil' type emulsion at 80 C.

was poured into water sufficient, at the same-temperature in a tall narrow vessel, to bring the concentration to 50% and stirred for 15 minutes at 80? Q withanEppenbach Homomixer;

care being taken to prevent incorporation of air into the oil-in-water emulsion. The stability and particle size of the emulsion were determined and the emulsion used to size test sheets of -kraft paper prepared as follows:

A 1% slurry of kraftpulp was beaten 2 hours The sized pulp was formed into wet sheets in p a sheet-making machine, pressed, and dried at 70 C. The sheets were conditioned for at least 2 hours at 75 .F. and 50% relative humidity before testing for water-resistance by the dry indicator. test and the fluorescence size test. In

the dry indicator tests a mixture of 1 part fuchsin dye, 50 parts sugar and 1 part starch ground and sieved through a -mesh screen was brushed onto approximately 2 sq. ins. of the paper and the specimen floated in water maintained at 75 F. The time in seconds for the first visible change in color in the indicator due to wetting was recorded. The fluorescent size tests were carried out as described by van den Akket et al. in the Paper TradeJournal, vol. 109, page 33 (1939). The following results were obtained;

1 7 Sfl llrr'g eiljidiengl'tdi' Y '1 *papercohec -pv I 011 in water emulsion been thickness of l o s tsg i y mils I i :8 0 wa er- 1H Slzing'agent 210 F. of ln-Qfl 4 g 7 siz'ing emulsion m 8 Fluoresagent -at 80 (I: -StalJllity-gt Stability upon Dryincence 50% copeendilution dlcator size $135101! to-1% test (secs) test (secs.)

Furtjurekextmcti motor oil of 79.8 very fiuiml Oil film on Some largepar- A few 're- 32 54 60 S.U.S.,viscosity at 210 F. surface. ticles coalmainder 15 to esced. majority be. Furiuralegrtract of motor QlLot 208 "(do "C'reamedbut Large partleles A few 10; re- 26 63 100S.U. S.'viscosityat210-F. no -coalessettled but nom'alnder 10 to 1 eenee. coalescence. majority ca. Frir'hir'zil extra'ctoflubrlcat-ing 392 ...do ..d0 Some large par- .do.... 47 261 dlljofilOQ-SPU. Swlscosltyafl ticles settled; 210 F. but no coalesv cence. Furl uraliextract or motor oil 416 Very fiuldi .-.'-do do..- j do. 298

(21%) S. U. S. viscosity at gel. v Fqrtgjal fertraetwr lgrqrlqa tipgi 2, 030 FluldzgeL; x'.;.d0--J-' .rdom; -A;f e v I0: re- 41 ms.

011 200 S. U. S. viscosifiy at mafmier 1 0 to 210 F. 7 4; majority -.l .l 3:--- .i' 7 Edeleiiitfxtizict of a topped. 4,500 .do do Large particles Some 20; re- 47: 194

Mld-sontliinficrude; settled. malinder zo to ymajorltyoa. Edeleanuextract olaMld-Con- 25,600 Fluid gel Partlilsep ador.; Mahy 20; re- 44- 300 tinent crude residue. e w h i c h ration after mainder- 20 to p o u r s 24 hrs. ZmiajOrity'da. l slowly. '4.

Slmflsr good results.- are obtained! when sulfite pulp-is used with thesesizes iirsteat of thel'rralft; V

Gooif-re'sr'il ts 'abre aIl'so'o taliifred" a heavyosphhlt (penetration r59) *i'n's'tejecd of the" aromatic extract the size. 013115? emulsifying ketone. The'oiFm-water emulsions? %"6011- centration was stable, although 'thi'e was 'some' es rsm'ing lilit stirring restores the enrrrl siarl to homogeneity. 0n summon to 1%, the. was "vry sfable with the majority or psrtms's less than 'I'mic'rohi'n diameter. Tes't 'sh't re In the absence of. a polyphosphorio acid com-- pound, the emulsions were too unstable and -incompleteto warrant size testing with thisyis cous sizing agent. i

In thesame way a seriesof sizing emulsions was prepared from a viscous aromatic extract of a Mid-Continent crude using 20%; of naphthenic acids of acid number-150 as the emulsifying agent and 0.375%to 115% ofsodium pyrcphosphate; together with 2% to 8% of isopropyl alcohol, as the solvent. In all cases good emulsion sizes of reduced viscosity compared with the corresponding emulsions without a polyphosphoric compound were obtained.

We claim as our invention:

1. A process of sizing paper. pulp which comprises contacting an aqueous slurry of the pulp with an aqueous emulsion of a hydrocarbon having a viscosity of 400 to 50,000 SUS at 210 F. containing 0.05% to 5% by weight of said hydrocarbon of a polyphosphoric acid compound together with mutual solvent for said polyphosphoric acid compound and hydrocarbon, and adding an acidic agent to precipitate said emulsion on the pulp.

2. A process of sizing fibrous materials which comprises precipitating on the fibers particles from an aqueous emulsion of a viscous hydrocarbon effective as a sizing agent produced by heating said hydrocarbon and naphthenic acids to form a fluid mixture thereof having a lower viscosity, intimately contacting said mixture with an aqueous solution of 0.05% to 5%, based on the weight of hydrocarbon sizing agent, of a polyphosphoric acid compound and sufficient oi a base to substantially neutralize the naphthenic acids, and diluting the resulting product with water to form an emulsion of the oil-in-water type.

3. A process of sizing cellulose fibers which comprises precipitating on the fibers particles from an emulsion of the oil-in-water type comprising 40% to 99% water, a liquid aromatic extract of petroleum hydrocarbons having a viscosity of at least 400 SUS at 210 R, an emulsifying agent in an amount of about 3% to about 75% of the total weight of emulsifying agent and hydrocarbon employed, and 0.05% to 5% by weight of said extract of a polyphosphoric acid compound.

4. A process of sizing paper pulp which comprises precipitating on the pulp particles from an emulsion of a cyclic extract from the extraction of a lubricating oil fraction of petroleum with a polar solvent having a preferential solubility for aromatic hydrocarbons in the presence of parafiins, 3% to 50% by weight of said extract of a water-soluble naphthenate, 0.25% to 5% based on the weight of said extract of a watersoluble alkali metal polyphosphoric acid salt, and at least 40 parts of water.

5. A process of sizing cellulose fibers which comprises precipitating on the fibers particles from an aqueous emulsion of a hydrocarbon having a viscosity of at least 400 SUS at 210 F., sufiicient sodium rosinate within the range of 5% to 50% f the total weight of sodium rosinate and hydrocarbon employed to emulsify said hydrocarbon, and 0.05% to by weight of said hydrocarbon of a water-soluble pyrophosphate, said emulsion being of the oil-in-water type and containing at least 40% of water.

6. A process of sizing cellulose fibers which comprises precipitating on the fibers particles from an aqueous emulsion of a sizing agent having a viscosity ofat' least'400 SUSa't 210? Hand 0.05% to 5%, based on the weight of said sizing agent, ofa polyphosphoric acid compound, said emulsion being of the oil-in watertype-and contai-ningat least of-water. V 1 #7. A-process of sizing fibrous material which comprises precipitating on-the-fibers particles from an emulsion of acyclic extract from-the extraction of alubricating oil fraction of petroleum with arsolvent having a preferential solubility for aromatic hydrocarbons in the presence of parafiins, together with 3% to of sodium salts of naphthenic acids having acid numbers less than 200, and 0.05% to 5% of a phosphate ester, said emulsion being of the oil-in-water type and containing at least 40% of water.

8. Fibrous material having on its surface a water-resistant coating precipitated from an aqueous emulsion comprising a sizing agent, an emulsifier therefor, and 0.05 to 5 based on the weight of said sizing agent, of a polyphosphoric acid compound.

9. A paper product comprising cellulose fibers having distributed on their surface about 0.5% to 5% by weight of the dry fibers of a precipitate from the alum treatment of an aqueous emulsion of a hydrocarbon having a viscosity of at least 400 SUS at 210 F., an emulsifying agent, and 0.05% to 5%, based on the weight of said hydrocarbon, of a water-soluble polyphosphate.

10. In a process of sizing fibrous material by precipitating a sizing agent thereon, the improvement which comprises precipitating onto the fibers suspended particles from an emulsion of a hydrocarbon sizing agent having a viscosity of at least 400 SUS at 210 F. and naphthenic acids, which emulsion is formed by intimately contacting a fluid mixture of said hydrocarbon and naphthenic acids with an aqueous solution containing 0.05% to 5% by weight, based on the weight of sizing agent present, of a pyrophosphoric acid compound and sufiicient of a base to substantially neutralize the naphthenic acids, and diluting the resulting product with water.

11. A process of sizing paper pulp which comprises precipitating on the pulp particles from an aqueous emulsion of petroleum hydrocarbons having a viscosity of at least 400 SUS at 210 F., 3% to 50% by weight of said hydrocarbons of sodium rosinate and 0.25% to 5% by weight of said hydrocarbons of sodium pyrophosphate, said emulsion being of the oil-in-water type and containing at least 40% of water.

12. A paper product comprising cellulose fibers having distributed on their surface about 0.5% to 5% by weight of the dry fibers of a precipitate from the alum treatment of an aqueous emulsion of a hydrocarbon having a viscosity of at least 400 SUS at 210 R, an emulsifying agent, and 0.05% to 20%, based on the weight of said hydro carbon, of a water-soluble polyphosphate.

ARTHUR B. BAKALAR. ROBERT D. SULLIVAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 53,094 Allen Mar. 13, 1866 577,135 Holmes Feb. 16, 1897 1,786,270 Spencer Dec. 23, 1930 1,786,462 Stryker Dec. 30, 1930 2,143,831 Ellis et a1 Jan. 10, 1939 (Other references on following page) um er PATENTS Natrre Date Draisbach 'Jan. 31, 1939 Mofitgomerie Aug. 8, 1939 Lingell Sept. 1'7, 194'0 Bradley July M, 1942 Krumbhaar May 1 8, 1943 Georgi et'al Dec. 2 1, I943 Goldstein 'e't-al May 22, 1945 Go'ldsteih et a1 May 22, F945 19 Number Number Name Date Gregg "it- July 1, 1:94? Hoelscher Nov. 4, 1947 FOREIGN PATENTS Country Date Great Britain Jan. 18, 1906 Switzerland May 31, 1930 Netherlands May 17, :1932 

1. A PROCESS OF SIZING PAPER PULP WHICH COMPRISES CONTACTING AN AQUEOUS SLURRY OF THE PULP WITH AN AQUEOUS EMULSION OF A HYDROCARBON HAVING A VISCOSITY OF 400 TO 50,000 SUS AT 210* F. CONTAINING 0.05% TO 5% BY WEIGHT OF SAID HYDROCARBON OF A POLYPHOSPHORIC ACID COMPOUND TOGETHER WITH MUTUAL SOLVENT FOR SAID POLYPHOSPHORIC ACID COMPOUND AND HYDROCARBON, AND ADDING AN ACIDIC AGENT TO PRECIPITATE SAID EMULSION ON THE PULP. 